Patent · US Expired

Method for active feedback suppression

US5010570A · kind A · utility

3Cited by
9References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 20, 1990
Grant dateApr 23, 1991
Priority date
Expiry dateFeb 20, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M9/08
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A process to reduce the howl condition in a radiotelephone when the microphone picks up audio from the speaker. The condition is detected by first lowering the speaker volume (103) and measuring the microphone volume for a corresponding decrease (104). The speaker volume is then increased (105) and the microphone volume is again measured for a corresponding increase (106). If the microphone volume follows the speaker volume, a howl condition has been detected. To eliminate the condition without the volume fluctuations being noticed by the parties conversing, the microphone and speaker volume is reduced in small increments (114) until the condition is eliminated.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.